Revert "Remove from_to abivars from Structure. These methods should be implemented in"
Revert "Remove from_to abivars from Structure. These methods should be implemented in"

This reverts commit 8ba536dca0eab2432912d5814abf3e546559b17d.

Bismarrck/pymatgen,Bismarrck/pymatgen,Bismarrck/pymatgen,Bismarrck/pymatgen,Bismarrck/pymatgen